The present invention relates to a skin graft preparation apparatus. Such apparatuses are generally known in the prior art. The purpose for such devices is to prepare skin for a skin graft in such a way that a small area of skin may be expanded to be grafted over a larger area on the patient. In this regard, an article by R. Peeters and A. Hubens, published in Burns, 1988, Vol. 14, No. 3, pp. 238-240, and titled "The Mesh Skin Graft--True Expansion Rate", discusses the effectiveness of pre-treatments of skin used for skin grafts. In the article, it was concluded that the expansion of skin after treatment in prior art skin graft preparation apparatuses never achieved the results which were claimed. Thus, for example, where a cutter mechanism was provided which was claimed to achieve a 3:1 expansion ratio, not a single treated skin graft reached this ratio. In fact, a significant number failed to even reach a 1.5:1 expansion ratio.
A further discussion of prior art skin graft preparation apparatuses is found in a publication titled "Treating the Burn Wound", pp. 97 through 107 thereof in particular. FIG. 6-5 thereof and the accompanying text describes and explains the uses of the Tanner Mesher, which is specifically described in U.S. Pat. No. 3,472,228 to Tanner, Jr. In this device, the cutting mechanism thereof is designed to provide a single ratio, for example, one of 1.5:1, 3:1, 6:1 or 9:1. It is important to note that each Tanner mesher machine incorporates a single one of the above-listed ratios therein and cutters of different ratios may not be interchanged therewith.
The following prior art is also known to applicant:
U.S. Pat. No. 3,472,228 to Tanner, Jr. was described above; additionally, U.S. Pat. No. 3,593,985 appears to disclose a refinement of the carrier mechanism of the Tanner, Jr. device described in U.S. Pat. No. 3,472,228.
U.S. Pat. No. 3,358,688 to Tanner, Jr. discloses a method of preparing skin for use in a skin graft. In this patent, two means are identified of meshing skin. A first method depicts a moving transverse bed of alternating cutters which travel beneath a pressure roll. A carrier made up of a stripping sheet and a pressure sheet between which a piece of skin is contained passes between the bed of cutters and the pressure roll. When the carrier and skin pass beneath the pressure roll, a cutting action is carried out. The second means uses the same general concept; however, the cutting bed has been transformed into a circular bed or cutting roll between which the carrier and skin pass. The alternating cuts are caused by machined areas within the length of the knife edge which are either circular or straight. The machined areas between the adjacent knife edges alternate.
U.S. Pat. No. 3,640,279 to Brown, et al. discloses a cylindrical bottom roll which utilizes angular slots as a means of providing an action similar to that of a flat grooved derma-carrier. There is nothing in this patent to teach or suggest changing of the angle of the slots to alter the length of a cut, nor as to a means to interchange a variety of bottom rolls having differently angled grooves.
U.S. Pat. No. 4,773,418 to Hettich discloses a device designed to be used to manufacture a skin graft by seeding skin from a cadaver with skin of a patient. The teachings of this patent are believed to be only generally related to the teachings of the present invention.
As such, a need has developed for a skin graft preparation apparatus which will achieve claimed ratios between the original area of the grafting skin and the area which is covered by the skin during a grafting procedure. A further need has developed for a skin graft preparation apparatus which includes parts which may easily be exchanged so as to avoid the significant expense of purchase of a single skin graft preparation apparatus for each desired ratio.
A further need has developed for a skin graft preparation apparatus having a superior means for guiding skin through the cutter mechanism thereof to achieve optimal results.
It is with these needs in mind that the present invention was developed.